👋🏻 this is Gene Liverman aka technicalissues on Twitter. I had an ah ha moment earlier and realize we had a much more secure option than Twitter DMs in which we could chat.

After you get the device I sent, you’ll want to do the following:

connect the usb cable to the microcontroller and a decent phone charger or similar
look for an ad hoc wireless network named jupiter-garage-data-setup and connect to it with the password self-hosted. I believe you’ll then be able to open the web interface of the device at http://192.168.4.1
once that’s working it’s then worth taking the yaml code I put in https://beanbag.technicalissues.us/jupiter-garage-data/ into ESPHome in Home Assistant. I’d do so by creating a new entry in the web interface either named jupiter-garage-data or some new name you want the device to have. Enter your actual WiFi creds. It’ll store those as secrets with the same name as what’s in my code.
Edit the new entry and copy/paste my code in and edit the top section. The key name needs to match what you called it in the last step. If you don’t want it to use dhcp you’ll need to edit the WiFi section of the yaml per https://esphome.io/components/wifi.html
tell the editor you want to install and that you’ll do so manually. Thus will build a firmware file and automatically download it in your browser. Be sure not to cancel in the middle of the build as it makes for a headache.
take the firmware file and upload it via the web interface from step 2. The device will reboot and should show up on your network.
ESPHome should connect to it and the link for logs should work. Once that’s true, Home Assistant should also discover the device automatically.

Once all that’s working, find yourself a place to mount the device. You’ll want to mount it with the microcontroller at the to sign that the heat it generates doesn’t skew the sensor readings. I suggest mounting it to the outside of the server rack/cabinet. The corded sensor I added can then be routed inside easily fir a secondary temperature reading.